摘要
通过对北京大学高频多普勒台站(39.4°N,116．2°E)多年的观测资料及相关台风资料的统计分析,着重研究了高频多普勒探测手段对由台风引起的扰动电离层响应的可探测性问题．通过对台风登陆前后的高频多普勒观测记录的细致分析及与宁静条件下记录的对比研究,表明高频多普勒观测手段可以很好地探测由台风激发的声重力波,尤其是对台风登陆前后所激发的扰动具有较高的可探测性．在所分析的24次台风事件中有明显扰动记录的高达22次(22/24)．结合观测事实与Huang等的统计结果(2/12)进行了比较,并进行了可能的原因分析．通过数值模拟的方法对观测到的主要扰动的非线性传播过程进行了模拟再现,结果基本上与观测结果及线性传播理论一致．确认了～般情况下高可探测性这一事实,但同时也表明可探测性和台风激发源与探测位置及中尺度TIDs在电离层中的传播模式有密切关系．
In this paper, the detectability of the ionospheric response to the typhoon-generated acoustic-gravity waves was studied through the statistical analysis of the HF Doppler shift records which come from the corresponding observation station at Peking University （39.4°N, 116.2°E） and a comparison with corresponding typhoon data. It is shown that the HF Doppler frequency sounding can be an effective tool for detecting the acoustic-gravity waves excited by typhoon, and the detectability is as high as up to 22 out of 24 for the present study. The detailed analysis of the HF Doppler records at different stages of the typhoon influenced period was made under the quiet conditions. Then, a comparison was made with the results of Huang （2 out of 12） and the possible causes of the differences between these two studies were analyzed. The non-linear propagation process of the main disturbances is reappeared by the method of numerical simulation, and the simulation results are in good agreement with observation results and the linear theory of acoustic-gravity waves propagated in the atmosphere. This confirmed that the detectability should be high in general. Also it is shown that the differences of detectability may be due to the fact that the detectability keeps a close correlation with the difference of relative locations of the source of typhoon and Doppler observation sites, and the propagation pattern of the medium-scale TIDs in the ionosphere.
出处
《空间科学学报》
CAS
CSCD
北大核心
2007年第1期35-40,共6页
Chinese Journal of Space Science
基金
中国科学院空间天气学国家重点实验室资助项目
关键词
高频多普勒探测
低层大气与高层大气耦合
电离层扰动
声重力波
HF Doppler shift sounding, Coupling between lower and upper atmosphere, Ionospheric disturbances, Acoustic-gravity waves
